CN112689839A

CN112689839A - Biometric imaging device

Info

Publication number: CN112689839A
Application number: CN201880097513.5A
Authority: CN
Inventors: 刘俊; 雷内·尼尔松; 伊赫桑·哈希米
Original assignee: Fingerprint Cards AB
Current assignee: Fingerprint kaana Kadun Intellectual Property Co.,Ltd.
Priority date: 2018-09-17
Filing date: 2018-09-17
Publication date: 2021-04-20
Also published as: EP3853760A4; WO2020056547A1; EP3853760A1; US11398110B2; US20220043998A1

Abstract

A biometric imaging apparatus (100) is configured to be arranged below an at least partially transparent display panel (102) and to capture images of objects located on opposite sides of the transparent display panel (102). A biometric imaging apparatus (100) comprises: an image sensor (108) comprising a photodetector pixel array (109); a transparent substrate (112) covering the photodetector pixel array (109); a first set of microlenses (118) configured to redirect light through the transparent substrate (112) and onto a sub-array of pixels (120) in the photodetector pixel array (109). The lenses in the first set of microlenses (118) have a first focal length. The second set of microlenses (119) is configured to redirect light through the transparent substrate (112) and onto a sub-array of pixels (121) in the photodetector pixel array (109). The second focal length of the lenses in the second set of microlenses (119) is different from the first focal length.

Description

Biometric imaging device

Technical Field

The present invention relates to a biometric imaging device configured to be disposed under an at least partially transparent display panel. The invention also relates to an electronic device.

Background

Biometric systems are widely used as a means for improving the convenience and security of personal electronic devices such as mobile phones. In particular, fingerprint sensing systems are now included in a large portion of all newly released consumer electronic devices, such as mobile phones.

Optical fingerprint sensors have been known for some time and may in some applications be a viable alternative to e.g. capacitive fingerprint sensors. The optical fingerprint sensor may be based, for example, on pinhole imaging principles and/or may employ micro-channels (i.e., collimators or micro-lenses) to focus incident light onto the image sensor.

US2015/0071648 describes an optical touch sensing device capable of detecting fingerprints in a fingerprint sensing mode and detecting touches or gestures in another mode. Optical touch sensing devices operate at two different resolutions by adjusting the number of photoconductive traces and metal traces of the sensing device being actively used. A change in the conductivity of the photoconductive trace indicates a change in the intensity of the incident light.

However, although the optical touch sensing device disclosed in US2015/0071648 is capable of detecting activity on the display, it is desirable to be able to detect a wider range of gestures, thereby enabling more complex user control operations via gestures.

It is therefore desirable to provide an improved optical fingerprint sensing device.

Disclosure of Invention

In view of the above-mentioned and other drawbacks of the prior art, it is an object of the present invention to provide a biometric imaging device that allows gesture recognition and fingerprint detection in different focal planes. An electronic device comprising such a biometric imaging device is also provided.

According to a first aspect of the present invention, there is provided a biometric imaging apparatus configured to be arranged below an at least partially transparent display panel and to capture images of an object located on opposite sides of the transparent display panel, the biometric imaging apparatus comprising: an image sensor comprising an array of photodetector pixels; a transparent substrate covering the photodetector pixel array; a first set of microlenses, wherein each microlens in the first set is configured to redirect light through the transparent substrate and onto a sub-array of pixels in the pixel array of photodetectors, wherein lenses in the first set of lenses have a first focal length; a second set of microlenses, wherein each microlens in the second set is configured to redirect light through the transparent substrate and onto a sub-array of pixels in the photodetector pixel array, wherein a second focal length of a lens in the second set of lenses is different from the first focal length.

The invention is based on the following recognition: two different sets of lenses having different focal lengths may be implemented for detecting objects at different distances from the biometric imaging device. One set of lenses may be adapted to detect objects at greater distances, such as hands and fingers, than another set of lenses. Alternatively, another set of lenses is adapted to detect, for example, a finger or fingerprint relatively close to the biometric imaging device.

The outer surface of the display panel below which the biometric imaging device is arranged may also be referred to as the sensing surface. The operating principle of the described biometric imaging apparatus is: light emitted by pixels in the display panel will be reflected by a finger placed on the sensing surface, and the reflected light is received by the microlenses and subsequently redirected onto a respective sub-array of pixels in the photodetector pixel array for each microlens. Thus, an image of a portion of a finger may be captured for each subarray, and by combining images from all microlenses, an image representing a fingerprint or gesture may be formed and subsequent biometric verification or gesture recognition may be performed.

With the claimed invention, a biometric imaging device is provided that is easily integrated in a display panel to provide an in-display fingerprint sensing function, and wherein the imaging device is also capable of detecting a finger or gesture performed in front of the biometric imaging device without having to touch the display panel.

Thus, the first set of microlenses may be configured to image objects touching on the outer surface of the transparent display panel, and the second set of microlenses may be configured to image objects at a distance from the outer surface of the transparent display panel.

In an embodiment, the second focal length may be longer than the first focal length.

According to an embodiment, the sub-array of pixels associated with the first set of microlenses and the sub-array of pixels associated with the second set of microlenses do not overlap. In order to more easily separate the detection light that has been redirected by one set of microlenses from the detection light that has been redirected by another set of microlenses, it is advantageous to configure them with respective pixel sub-arrays that do not overlap. Thus, one sub-array of pixels that can receive light from a first set of microlenses may not be able to receive light from another set of microlenses at the same time. The sub-arrays differ from each other in this way. The size of the subarray may be in the range of 20 μm to 2 mm.

According to an embodiment, the second set of microlenses may be more sparsely distributed than the first set of lenses. Thus, the density of the microlenses in the second group may be lower than the density of the microlenses in the first group.

According to an embodiment, the first and second sets of microlenses may be arranged in a combined microlens array. In other words, the first and second sets of microlenses may be mixedly arranged in a single array layout.

According to an embodiment, the first set of microlenses may be arranged in an array having a pitch in the range of 50 μm to 2 mm.

According to an embodiment, the second group of microlenses may be arranged in an array having a pitch greater than or equal to the pitch of the first group of lenses. The array may be arranged in any pattern, such as a square, rectangular or hexagonal array.

According to an embodiment, the lenses in the first group may be circular lenses having a diameter in the range of 20 μm to 1 mm.

According to an embodiment, the microlenses in the first group are rectangular lenses whose shortest sides have a length in the range of 20 μm to 1 mm.

According to an embodiment, the radius of curvature of the lenses in the first group is smaller than the radius of curvature of the lenses in the second group. The radius of curvature may be a radius of curvature of a light receiving surface of the microlens, i.e., a surface facing the display panel. Alternatively, in some embodiments, the radius of curvature may be a radius of curvature of a surface facing the image sensor.

Further, the height of the microlens may be in the range of 2 μm to 600 μm.

With the above possible configurations of multiple microlenses, an optical fingerprint sensor for use under the display panel may be provided, and the particular configuration may be adjusted based on the characteristics of the display panel and the requirements of the application at hand.

According to an embodiment, the first set of microlenses may be configured to redirect light to a light sensitive pixel array for fingerprint detection, and the second set of microlenses may be configured to redirect light to a light sensitive pixel array for gesture control functions of the electronic device.

According to an embodiment, the first and second sets of microlenses are arranged on a transparent substrate, the transparent substrate being arranged to cover the image sensor. This simplifies the fabrication of the biometric imaging device, since the microlenses can all be fabricated on the same transparent substrate. Furthermore, arranging all the microlenses on a single substrate facilitates the task of having the microlenses in a single plane.

The microlenses are preferably configured to focus light onto the respective pixel sub-arrays.

According to a second aspect of the present invention, there is provided an electronic apparatus comprising: a transparent display panel; a biometric imaging apparatus according to any one of the preceding claims, and a processing circuit configured to: the method includes receiving a signal from a biometric imaging device indicative of a detection object located at a distance from an outer display surface of a transparent display panel, determining a gesture or shape of the detection object, and performing at least one action based on the detected gesture or shape.

The display panel may for example be based on OLED, LCD, μ LED and similar technologies. Thereby enabling imaging of the biological feature in the display.

According to an embodiment, the processing circuitry may be configured to: a signal indicative of a fingerprint of a finger touching the transparent display panel is received from the biometric imaging device, and a fingerprint authentication process is performed based on the detected fingerprint.

The detection object may be a hand of a user.

The at least one action may include a navigation event, zoom, volume control, typing, display control on the electronic device.

The electronic device may be, for example, a mobile device, such as a mobile phone (e.g., a smartphone), a tablet computer, a tablet handset, and so forth.

Further effects and features of the second aspect of the invention are largely analogous to those described above in connection with the first aspect of the invention.

Other features and advantages of the invention will become apparent when studying the appended claims and the following description. The skilled person realizes that different features of the present invention can be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.

Drawings

These and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing exemplary embodiments of the invention, wherein:

fig. 1 schematically shows an example of an electronic device according to an embodiment of the invention;

FIG. 2 is a schematic block diagram of an electronic device according to an embodiment of the invention;

FIG. 3 schematically illustrates a biometric imaging device according to an embodiment of the invention;

FIG. 4 schematically illustrates a biometric imaging device according to an embodiment of the invention;

FIG. 5a conceptually illustrates a finger touching the transparent panel and a first set of microlenses having a first focal length;

fig. 5b schematically shows an object performing a gesture and a second set of microlenses having a second focal length.

Detailed Description

In the present detailed description, various embodiments of the biometric imaging device according to the present invention are described mainly with reference to the biometric imaging device disposed below the display panel. It should be noted, however, that the described imaging device may also be used in other optical fingerprint imaging applications, for example in an optical fingerprint sensor located underneath a cover glass or the like.

Turning now to the drawings and in particular to fig. 1, fig. 1 schematically illustrates an example of an electronic device in the form of a mobile device 101 with an integrated in-display biometric imaging device 100 and a display panel 104, the display panel 104 having a touch screen interface 106, configured to apply concepts according to the present disclosure. The biometric imaging device 100 may be used, for example, to unlock the mobile device 100 and/or to authorize a transaction performed using the mobile device 100, or the like. Further, the biometric imaging device 100 may also be used for gesture recognition performed by the user to control actions on the electronic device.

Preferably and as will be apparent to those skilled in the art, the mobile device 100 shown in fig. 1 further comprises a first antenna for WLAN/Wi-Fi communication, a second antenna for telecommunication communication, a microphone, a speaker and a phone control unit. Of course, the mobile device may also include other hardware elements.

It should also be noted that the present invention may be applicable with respect to any other type of electronic device that includes a transparent display panel, such as a laptop computer, a tablet computer, and the like.

Fig. 2 is a schematic block diagram of an electronic device according to an embodiment of the present invention. According to an embodiment of the present invention, the electronic device 200 includes a transparent display panel 204 and the biometric imaging device 100, the biometric imaging device 100 being conceptually shown as being disposed below the transparent display panel 204. Furthermore, the electronic device 200 comprises processing circuitry, such as a control unit 202. The control unit 202 may be a separate control unit of the electronic device 400, such as a device controller. Alternatively, the control unit 202 may be included in the biometric imaging apparatus 100.

The control unit 202 is configured to receive a signal indicative of a detection object from the biometric imaging apparatus 100. The received signal may include image data. The detection object may be positioned away from, i.e., not in contact with, the outer display surface of the transparent display panel 204.

Based on the received signal, the control unit 202 is configured to determine a gesture or a shape of the detected object, or both. The control unit 202 may detect the shape and/or gesture of the object using image recognition methods that are considered to be known.

The control unit 202 is configured to perform at least one action based on the detected gesture and/or shape of the object. Thus, the shape and/or gesture performed by the object may be used to control a function on the electronic device. The gestures and/or shapes of the objects may be extracted from images captured by the biometric imaging device 100. Gesture control of an electronic device may be performed in three dimensions (i.e., x, y, z) to control various functions on the electronic device.

Some example applications that may be controlled by, for example, the shape of a hand or a gesture performed by a hand or fingers of a hand include: changing speaker volume (z direction) or going to the next song (x-y direction), waking up or sleeping the display screen using different finger gestures, zooming in or out of a picture or page, scrolling through a document or web page, displaying fingerprint touch locations using finger motion floating on the display panel, typing text using finger motion floating on the display panel, changing menus with a hand swipe, etc.

Fig. 3 schematically shows a biometric imaging apparatus 100 according to an embodiment of the invention. Here, the biometric imaging device 100 is arranged below the at least partially transparent display panel 102. However, the biometric imaging device 100 may be disposed under any sufficiently transparent cover structure, as long as the image sensor receives a sufficient amount of light to capture an image of a biometric object, such as a fingerprint or palm print, in contact with an outer surface of the cover structure, or to detect an object further away from the outer surface for gesture detection. Hereinafter, the biometric imaging device 100 configured to capture an image of the finger 104 in contact with the outer surface 106 of the display panel 102 and configured to detect a gesture performed by a hand not in contact with the display panel 102 will be described.

The biometric imaging apparatus 100 includes an image sensor 108, the image sensor 108 including an array of photodetector pixels 109, wherein each pixel 110 is an individually controllable photodetector configured to detect an amount of incident light and generate an electrical signal indicative of light received by the detector. The image sensor 108 may be any suitable type of image sensor, such as a CMOS or CCD sensor connected to associated control circuitry. The operation and control of such image sensors may be considered known and will not be discussed herein.

The biometric imaging apparatus 100 further includes: a transparent substrate 112 arranged to cover the image sensor 108; an opaque layer 114 covering the upper surface of the transparent substrate 112. The opaque layer 114 further comprises a plurality of separate openings 116 arranged at a distance from each other; and two sets of

microlenses

118, 119 having different focal lengths.

The biometric imaging device includes two sets of microlenses. Here two lenses 118 in the first set and one lens 119 in the second set are shown. The focal length of the lens 118 in the first group is different from the focal length of the lens 119 in the second group. Each

microlens

118, 119 is disposed in a respective opening 116 of the optional opaque layer 114 that is coplanar with the opaque layer 114. Further, the size and shape of the

microlenses

118, 119 is the same as the size and shape of the opening 116 to prevent any stray light that does not pass through the

microlenses

118, 119 from reaching the image sensor 108.

Each

microlens

118, 119 is configured to redirect light through the transparent substrate 112 and onto a sub-array of

pixels

120, 121 in the photodetector pixel array 109. The sub-arrays 120, 121 are defined herein as an array of pixels receiving light from only one

microlens

118, 119. It should also be noted that the

microlenses

118, 119 and display pixels are not drawn to scale. The

microlenses

118, 119 are shown to receive light reflected by the finger 104, which has propagated through the display panel 102 before reaching the

microlenses

118, 119, and the light received by the

microlenses

118, 119 is focused onto the image sensor 108. The sub-array of pixels 120 receiving light from the first set of microlenses 118 preferably does not overlap the sub-array of pixels 121 receiving light from the second set of microlenses 119.

The

microlenses

118, 119 are shown here as plano-convex lenses having flat surfaces oriented toward the transparent substrate. Other lens configurations and shapes may also be used. The plano-convex lens may, for example, be arranged with the flat surface facing the display panel 102, and in one embodiment, the lens may be attached to the lower surface of the display panel 102, although imaging performance may be reduced compared to the reverse orientation of the lenticules. Other types of lenses, such as convex lenses, may also be used. The advantage of using a plano-convex lens is that the manufacturing and assembly provided by a lens having a flat surface is easy.

The biometric imaging device 100 also includes an intermediate layer 122 located between the opaque layer 114 and the display panel 102. The intermediate layer 122 may, for example, comprise an adhesive layer for attaching the display panel 102 to the imaging device 100, and the refractive index of the intermediate layer 122 is different from the refractive index of the

microlenses

118, 119. The intermediate layer comprises an air gap between the transparent display panel and the

lenses

119, 118. In addition, the intermediate layer 122 may also include an anti-reflective coating, a filter, and/or a polarizing filter, which are not separately illustrated herein. It is generally preferred that the refractive index of the

microlenses

118, 119 be as high as possible and different from the refractive index of any adjacent material above or below the microlenses 118.

Fig. 4 is an exploded view of the biometric imaging device 100, more clearly showing the sub-arrays of

pixels

120, 121 in the pixel array 109 receiving light from one

microlens

118, 119. Here, the

microlenses

118, 119 are shown as circular plano-convex lenses providing circular sub-arrays of

pixels

120, 121. Rectangular microlenses can also be used, which would result in an approximately rectangular sub-array of pixels. The pitch of the

microlenses

118, 119 is at least greater than half the size of the

respective subarray

120, 121, or greater than the diameter of the

respective microlens

118, 119, whichever is the largest, regardless of the half the size of the

respective subarray

120, 121 and the diameter of the

microlens

118, 119. For a circular microlens 118, the diameter of the microlens 118 may be in the range of 20 μm to 1mm, and for a rectangular microlens, the length of the shortest side may be in the range of 20 μm to 1 mm. Further, the height of the

microlenses

118, 119 is in the range of 2 μm to 600 μm, and are arranged in a sparse array configuration having a pitch in the range of 50 μm to 2 mm. All of the

microlenses

118, 119 within each group of microlenses preferably have the same size and shape.

In fig. 4, it can also be seen that

subarrays

120 and or 121 do not overlap, which is preferred, although it may not be strictly required. Thus, each microlens 118 redirects light onto a pixel array 120 comprising a plurality of light sensing elements such that an image is captured by the sub-array 120 for the respective microlens 118. Similarly, each microlens 119 redirects light onto a pixel array 121 comprising a plurality of light sensing elements, such that an image is captured by the sub-array 121 for the respective microlens 119. Each image represents a portion of a fingerprint or another object, and by combining the captured images, a complete image of the finger or object may be obtained and used for further authentication and verification or for gesture control functions. The image analysis required to derive a fingerprint image or extract a gesture after capturing a plurality of images from a plurality of sub-arrays may be performed in a number of different ways and will not be discussed in detail herein.

It can be noted that for capturing an image of a fingerprint, only the sub-arrays located directly below the finger need to be activated, providing energy efficient and fast image capture. Furthermore, the activation of the sub-arrays may be performed sequentially, so that not all sub-arrays need to be activated at the same time, thereby enabling the use of simplified readout circuitry.

The biometric imaging device is capable of imaging an object, such as a fingerprint, that touches the outer surface of the transparent display panel. Furthermore, the biometric imaging device is also capable of imaging an object located at a distance from the outer surface of the transparent display panel. This is schematically illustrated in fig. 5a to 5 b.

Fig. 5a schematically shows a finger 104 touching the transparent panel 106. Fig. 5b shows a hand 304 performing a gesture at a distance from the outer surface of the transparent display panel.

Figure 5a conceptually illustrates a finger 104 touching the transparent panel 106 and a first set of lenses 118 having a first focal length. The first group of lenses has a focal length suitable for focusing light redirected from a fingerprint of a finger located near lens 118. Thus, the first set of lenses 118 is configured to redirect light to the array of light sensitive pixels for fingerprint detection.

Further, the second group of lenses is configured to redirect light to the array of light sensitive pixels 108 for gesture control functions. In other words, and as conceptually illustrated in fig. 5b, the second group of lenses 119 is adapted with a focal length that enables, for example, gestures to be performed by the hand 304 at a relatively large distance from the biometric imaging device 100. The hand 304 and biometric imaging device 100 are not scaled to scale.

It is well known that the focal length of a lens is closely related to the field of view of the lens. For a given sensor, a shorter focal length also means a wider field of view. Accordingly, the focal length of the first group lens 118 is shorter than the focal length of the second group lens 119, resulting in a wider field angle 502 shown in fig. 5a than a field angle 503 of the second group lens 119 shown in fig. 5 b. This means that the second set of lenses 119 having a longer focal length is better suited for imaging of objects further away from the biometric imaging apparatus 100 than the first set of lenses 118. In the same way, the first set of lenses 118 having a shorter focal length is better suited for imaging of objects closer to the biometric imaging apparatus 100 than the second set of lenses 119.

There are various ways to configure the lens to have different focal lengths. One method is to adjust the radius of curvature of the lens. In one embodiment, the radius of curvature of the lens 118 in the first group is smaller than the radius of curvature of the lens 119 in the second group. This is the case, for example, in the embodiment shown in fig. 5 a.

The control unit may include a microprocessor, microcontroller, programmable digital signal processor, or other programmable device. The control unit may also or alternatively comprise an application specific integrated circuit, a programmable gate array or programmable array logic, a programmable logic device or a digital signal processor. Where the control unit comprises a programmable device (e.g. a microprocessor, microcontroller or programmable digital signal processor as mentioned above), the processor may also comprise computer executable code which controls the operation of the programmable device. It should be understood that all or some of the functionality provided by means of the control unit (or "processing circuitry" in general) may be at least partially integrated with the biometric imaging device.

While the present invention has been described with reference to specific exemplary embodiments thereof, many different alterations, modifications and the like will become apparent for those skilled in the art. Moreover, it should be noted that the components of the imaging apparatus and the method for manufacturing the imaging apparatus may be omitted, interchanged or arranged in various ways and the imaging apparatus is still capable of performing the functions of the present invention.

In addition, variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. A biometric imaging apparatus (100) configured to be disposed under an at least partially transparent display panel (102) and to capture images of objects located on opposite sides of the transparent display panel, the biometric imaging apparatus comprising:

-an image sensor (108) comprising a photodetector pixel array (109);

-a transparent substrate (112) covering the photodetector pixel array;

-a first set of microlenses (118), wherein each microlens in the first set is configured to redirect light through the transparent substrate and onto a sub-array of pixels (120) in the photodetector pixel array, wherein the lenses in the first set of lenses have a first focal length;

-a second set of microlenses (119), wherein each microlens in the second set is configured to redirect light through the transparent substrate and onto a sub-array of pixels (121) in the photodetector pixel array, wherein a second focal length of a lens in the second set of lenses is different from the first focal length.

2. The biometric imaging apparatus as in claim 1, wherein the first set of microlenses is configured to image an object touching on an outer surface of the transparent display panel and the second set of microlenses is configured to image an object at a distance from the outer surface of the transparent display panel.

3. The biometric imaging apparatus as set forth in any one of claims 1 and 2, wherein the second focal length is longer than the first focal length.

4. The biometric imaging apparatus as set forth in any one of the preceding claims, wherein the sub-array (120) associated with the first set of microlenses and the sub-array (121) associated with the second set of microlenses do not overlap.

5. The biometric imaging apparatus as in any one of the preceding claims, wherein said second set of microlenses are more sparsely distributed than said first set of lenses.

6. The biometric imaging apparatus according to any one of the preceding claims, wherein said first set of microlenses and said second set of microlenses are arranged in a combined microlens array.

7. The biometric imaging apparatus according to any one of the preceding claims, wherein said first set of microlenses are arranged in an array having a pitch in the range of 50 μ ι η to 2 mm.

8. The biometric imaging apparatus according to any one of the preceding claims wherein said second set of microlenses is arranged in an array having a pitch greater than or equal to the pitch of said first set of lenses.

9. A biometric imaging apparatus as in any one of the preceding claims, wherein said lenses of said first group are circular lenses having a diameter in the range of 20 μm to 1 mm.

10. The biometric imaging apparatus according to any one of claims 1 to 8, wherein the microlenses in said first group are rectangular lenses having a length of the shortest side in the range of 20 μm to 1 mm.

11. A biometric imaging apparatus as in any one of the preceding claims, wherein a radius of curvature of the lenses in said first group is less than a radius of curvature of the lenses in said second group.

12. The biometric imaging apparatus according to any one of the preceding claims, wherein said first set of micro-lenses is configured for redirecting light to a light sensitive pixel array for fingerprint detection and said second set of micro-lenses is configured for redirecting light to a light sensitive pixel array for gesture control functions of an electronic device.

13. The biometric imaging apparatus according to any one of the preceding claims, wherein said first and second sets of microlenses are disposed on said transparent substrate, said transparent substrate being disposed to cover said image sensor.

14. The biometric imaging apparatus according to any one of the preceding claims wherein said microlenses are configured to focus light onto respective sub-arrays of pixels.

15. An electronic device, comprising:

-a transparent display panel;

-a biometric imaging apparatus according to any of the preceding claims, and

-a processing circuit configured to:

-receiving a signal from the biometric imaging device indicative of a detection object located at a distance from an outer display surface of the transparent display panel,

-determining a gesture or shape of the detected object, an

-performing at least one action based on the detected gesture or shape.

16. The electronic device of claim 15, wherein the processing circuit is configured to:

-receiving a signal from the biometric imaging device indicative of a fingerprint of a finger touching the transparent display panel,

-performing a fingerprint authentication procedure based on the detected fingerprint.

17. The electronic device of any of claims 15 and 16, wherein the detection object is a hand of a user.

18. The electronic device of any of claims 15-17, wherein the at least one action includes a navigation event, zoom, volume control, typing, display control on the electronic device.

19. The electronic device of any of claims 15-18, wherein the electronic device is a mobile phone.